Plasmons are quasiparticles resulting from the quantization of plasma oscillations, just as photons and phonons are quantizations of light and sound waves, respectively. Surface plasmons are those plasmons that are confined to surfaces and that interact strongly with light. They occur at the interface of a vacuum or material with a positive dielectric constant with that of a negative dielectric constant (usually a highly conductive material such as a conductive or doped semiconductor).
Plasmonics is a field where one exploits the short wavelength of a surface plasmon in an analogous method as one exploits an optical wavelength for information transfer or data manipulation. But, rather than a quantum of light (a photon), a plasmon, or collective excitation in the electron density, is used.
Plasmons have also been proposed as a means of high-resolution lithography and microscopy due to their extremely small wavelengths. Both of these applications have seen successful demonstrations in the lab environment. Additionally, surface plasmons have the unique capacity to confine light to very small dimensions which could enable many new applications. Plasmons have also been considered as a means of transmitting information on computer chips, since plasmons can support much higher frequencies (into the 100 THz range, while conventional wires become very lossy in the tens of GHz). But for plasmon-based electronics to be useful, a device that allows for control of the propagation of surface plasmons is needed.
In view of the above, it is an object of the present invention to provide a plasmonic router that allows for selective propagation of a surface plasmon through a surface plasmon guide. It is another object of the present invention to provide a plasmonic router that allows for selective propagation of a surface plasmon from one surface plasmon guide to another surface plasmon guide. Still another object of the present invention is to provide a plasmonic router that can be fabricated using existing complementary conductive metal-oxide-semiconductor (CMOS) technology. Another object of the present invention is to device a plasmonic router that is relatively easy to manufacture in a cost-efficient manner.